16-004 Specifications for 26003270.pdf

Specifications

For

26003270

Micro-Surfacing and/or Slurry Seal

1. SCOPE

The work covered by this specification includes the design, testing, construction, and quality control required for the proper application of micro-surfacing and slurry seal treatment services.

Micro-Surfacing This application is used to give maximum skid resistance and an improved wearing surface.

An example would be on pavements which have high traffic volume. Rate of application: 25 to 28 pounds per square yard of dry aggregate minimum.

Slurry Seal TYPE IIA: This application is used to give maximum skid resistance and an improved wearing surface. An example would be on pavements which have a highly textured surface and require this size aggregate to fill in the voids and provides an improved wearing surface. Rate of application: 15 to 18 pounds per square yard of dry aggregate minimum.

2. DESCRIPTION

Both the Micro-Surfacing and the Slurry Seal shall consist of a mixture of an approved emulsified asphalt, mineral aggregate, mineral filler, and water and specified additives, proportioned, mixed and uniformly spread over a properly prepared surface. The completed micro-surface shall leave a homogenous mat, adhere firmly to the prepared surface and have a skid resistant surface texture.

The streets to be treated are shown on the attached lists and maps.

3. LABORATORY EVALUATION

Before work commences, the Contractor shall submit a signed original of a mix design containing the test results and proportioning of the specific materials to be used on the project. This design shall have been performed by a qualified laboratory. Previous lab reports covering the exact materials to be used may be accepted provided they were made during the calendar year. This initial mix design will be done at the Contractor’s expense. Upon receipt of the original mix design, an independent qualified laboratory selected by the City may perform tests using the same materials as used in the initial mix design for verification of the results. This testing will be done at the City’s expense. No work will begin until all the materials and/or mix design proportions have met the specifications as required. Once the materials are approved, no substitutions will be permitted unless first tested and approved by the methods stated above.

4. APPLICABLE SPECIFICATIONS

The following specifications and test methods form a part of this specification.

AASHTO: American Association of State Highway and Transportation Officials

ASTM: American Society for Testing and Materials ISSA: International Slurry Seal Association

AGGREGATE AND MINERAL FILLER

AASHTO TEST

NO.

ASTM TEST

NO.

TEST

T 2 D 75 Sampling Aggregates T 27 C136 Sieve Analysis of Aggregates T 11 C117 Materials Finer than No. 200 in Mineral Aggregate

T 176 D 2419 Sand Equivalent Value of Soils and Fine Aggregate T 19 C 29 Bulk Density (“Unit Weight”) and Voids in Aggregate

T 104 C 88 Soundness of Aggregates by use of Sodium Sulfate or Magnesium Sulfate

T 96 C 131 Resistance to Degradation of Small Size Aggregate by Abrasion and Impact in the Los Angeles Machine

M17 D 242 Mineral Filler for Bituminous Paving Mixtures

EMULSIFIED ASPHALTS

AASHTO TEST

NO.

ASTM TEST

NO.

TEST

T 40 D 140 Sampling Bituminous Materials M 140 D 977 Specifications for Emulsified Asphalt M 208 D 2397 Specifications for Cationic Emulsified Asphalt T 59 D 244 Testing Emulsified Asphalt T 59 D 6997 Distillation of Emulsified Asphalt

SLURRY SEAL SYSTEM

ISSA TEST NO. ASTM NO. TEST

A105 Design, Testing, and Construction of Slurry Seal

TB 100 Test Method for Wet Track Abrasion of Slurry Surfaces TB 101 Guide for Sampling Slurry Mix Extraction Test TB 106 Measurement of Slurry Seal Consistency

TB 109

Test Method for Measurement of Excess Asphalt in

Bituminous Mixtures by Use of a Loaded Wheel Tester TB 111 Outline Guide Design Procedure for Slurry Seal

TB 112

Method of Estimate Slurry Seal Spread Rates and to

Measure Pavement Macrotexture TB 113 Trail Mix Procedures for Slurry Seal Design TB 114 Wet Stripping Test for Cured Slurry Seal Mixes TB 115 Determination of Slurry Seal Compatibility

TB 139

Method of Classified Emulsified Asphalt, Aggregate Mixtures by

Modified Cohesion Test Measurement of Set and Cure Characteristics

MATERIALS

5. AGGREGATE

The mineral aggregate shall consist of a natural or manufactured crushed stone such as granite, slag, limestone or other high-quality aggregates or a combination thereof and shall be free of dirt, organic matter, clay balls, and adherent films of clay, dust or other objectionable material. The aggregate shall contain no free water.

5.1 Quality Tests

The aggregate should meet the specified polishing values and these minimum requirements:

TEST Test Method Specification

AASHTO ASTM

Sand Equivalent Value of Soils and Fine Aggregate

T 176 D 2419 45 Minimum – Slurry 65 Minimum - Micro

Soundness of Aggregates by Use of Sodium Sulfate of Magnesium Sulfate

T 104 C 88 15% Maximum w/NA2SO4 25% Maximum w/MgSO4

Resistance to Degradation of Small- Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine1

T96 C 131 35% Maximum – Slurry 30% Maximum – Micro

1The abrasion test is run on the parent aggregate.

5.2 GRADATION

When tested in accordance with AASHTO T 27 (ASTM C 136) and AASHTO T 11 (ASTM C 117), the mix design aggregate gradation shall be within one of the following bands (or one recognized by the local paving authority1):

SIEVE

SIZE

TYPE I

PERCENT

PASSING

TYPE II

PERCENT

PASSING

TYPE III

PERCENT

PASSING

STOCKPILE

TOLERANCE FROM

THE MIX DESIGN

GRADATION

3/8 (9.5 mm) 100 100 100 #4 (4.75 mm) 100 90-100 70-90 ±5% #8 (2.36 mm) 90-100 65-90 45-70 ±5% #16 (1.18 mm) 65-90 45-70 28-50 ±5% #30 (600 um) 40-65 30-50 19-34 ±5% #50 (330 um) 25-42 18-30 12-25 ±4% #100 (150 um) 15-30 10-21 7-18 ±3% #200 (75 um) 10-20 5-15 5-15 ±2%

1The City of Midland will also accept the following bands for Type II Gradation:

Slurry Seal

SIEVE

SIZE

TYPE II PERCENT

PASSING

STOCKPILE

TOLERANCE FROM

THE MIX DESIGN

GRADATION

3/8 (9.5 mm) 100 #4 (4.75 mm) 85-100 ±5% #8 (2.36 mm) 55-80 ±5% #16 (1.18 mm) 35-60 ±5% #30 (600 um) 25-45 ±5% #50 (330 um) 18-30 ±4% #100 (150 um) 10-21 ±3% #200 (75 um) 5-15 ±2%

Micro-Surface

SIEVE

SIZE

TxDOT Grade II

PERCENT

PASSING

STOCKPILE

TOLERANCE FROM

THE MIX DESIGN

GRADATION

3/8 (9.5 mm) 100 #4 (4.75 mm) 86-94 ±5% #8 (2.36 mm) 45-65 ±5% #16 (1.18 mm) 25-46 ±5% #30 (600 um) 15-35 ±5% #50 (330 um) 10-25 ±4% #100 (150 um) 7-18 ±3% #200 (75 um) 5-15 ±2%

The gradation of the aggregate stockpile shall not vary by more than the stockpile tolerance from the mix design gradation (indicated in the table above) while also remaining within the specification gradation band. The percentage of aggregate passing any two sieves shall not change from one end of the specified range to the other end.

The aggregate will be accepted at the job location or stockpile based on five gradation tests sampled according to AASHTO T 2 (ASTM D 75). If the average of the five tests is within the stockpile tolerance from the mix design gradation, the material will be accepted. If the average of those test results is out of specification or tolerance, the Contractor will be given the choice to either remove the material or blend additional aggregate with the stockpile material to bring it into compliance. Material used in blending must meet the required aggregate quality test specification in Section 5.1 before blending and must be blended in a manner to produce a consistent gradation. Aggregate blending may require a new mix design.

Screening shall be required at the stockpile.

6. MINERAL FILLER

Mineral filler may be used to improve mixture consistency and to adjust mixture breaking and curing properties. Provide mineral filler that is sufficiently dry, free-flowing, and free of clumps and foreign matter consisting of portland cement, hydrated lime, or other approved filler meeting the requirements of ASTM D 242. Use mineral filler if required by the mix design. Typical use levels are normally 0.0-3.0 percent and may be considered part of the aggregate gradation.

7. WATER

All water shall be potable and compatible with the micro-surfacing and slurry seal mix and free of harmful soluble salts. Compatibility shall be ensured by the Contractor. The percent of water in the mix design shall produce proper mix consistency.

8. EMULSIFIED ASPHALT – The asphalt emulsion shall be homogenous and show no separation after mixing.

Micro-Surfacing and/or Slurry Seal – The emulsified asphalt shall be polymer modified. The polymer material shall be milled or blended into the asphalt or emulsifier solution prior to the emulsification process. In general, three percent (3%) polymer solids, based on asphalt weight, is considered minimum.

Cationic Polymer-Modified Asphalt Emulsion.

CSS-1EP meeting the requirements of the following table:

Polymer-Modified Cationic Emulsified Asphalt

Property Test Procedure

Emulsion CSS-1EP

Minimum Maximum Asphalt Base Properties

Original DSR, kPa (G*/sin δ, 10 rad./sec) @ 76ºC T315 1.00

Emulsion Properties Viscosity, Say bolt-Furol, @122ºF, SFS T59 15 150

Sieve Test, % T59 0.1 Distillation Test

Residue by distillation, % by weight T59 62 Oil distillate, % by volume of emulsion T59 .05

Tests on Residue Properties from Low Temp Evaporation (AASHTO R-781) MSCR @ 70ºC, Recovery @ 3.2 kPa, % T350 80

MSCR @ 70ºC, Jnr @3.2, 1/kPa T350 0.50 ODSR, kPa (G*/sin δ, 10 rad./sec) @ 76ºC T315 1

ODSR, deg (phase angle δ, 10 rad./sec) @ 76ºC T315 60

1After recovering the residue from AASHTO R-78, the sample may be annealed before testing to remove any excess moisture and provide for a consistent sample. The Annealing can be accomplished by placing 20 g of residue in a 6 oz. metal container (approximately 3” diameter) and heating to 163ºC for no more than 15 minutes. The sample should be stirred with a spatula every 5 minutes. The sample can then be poured directly into a 25mm DSR silicone mold for evaluation.

9. Latex Modifier

Micro-surfacing and Slurry Seal will have latex content sufficient to meet the mix design.

10. ADDITIVES

Additives may be used to accelerate or retard the break/set of the slurry seal and/or the micro surfacing. Appropriate additives, and their applicable use range, should be approved by the laboratory as part of the mix design.

TEST AND DESIGN

11. General Before work begins, the contractor shall submit a sign mix design covering the specific materials to be used on the project. This design will be performed by a laboratory which has experience in designing Emulsified Asphalt Slurry Seal Surfacing and/or Micro Surfacing. After the mix design has been approved, no material substitution will be permitted unless approved by the B.A.R.

12. MIX DESIGN

Compatibility of the aggregate, emulsified asphalt (slurry)/polymer-modified emulsified asphalt (micro), water, mineral filler and other additives shall be evaluated in the mix design. The mix design shall be completed using materials consistent with those supplied by the Contractor for the project. Recommended tests and values are as follows:

12.1 SLURRY SEAL

TEST ISSA TB NO. SPECIFICATION

Mix Time @ 77° F (25° C) TB 113 Controllable to 180 Seconds Min.

Slurry Seal Consistency TB 106 0.79 – 1.18 inches (2.0 – 3.0 cm) Wet Cohesion @ 30 Minutes Minimum (Set) @ 60 Minutes Minimum (Traffic)

TB 139

(for quick-traffic systems)

12 kg-cm Minimum 20 kg-cm Minimum or Near Spin Min.

Wet Stripping TB 114 Pass (90% Minimum) Wet-Track Abrasion Loss One-hour Soak

TB 100 75 g/ft2 (807 g/m2) Maximum

Excess Asphalt by LWT Sand Adhesion

TB 109

(Critical in heavy-traffic areas)

50 g/ft2 (538 g/m2) Maximum

12.2 Micro Surface

TEST ISSA TB NO. SPECIFICATION

Mix Time @ 77° F (25° C) TB 113 Controllable to 120 Seconds Min.

Wet Cohesion @ 30 Minutes Minimum (Set) @ 60 Minutes Minimum (Traffic)

TB 139

12 kg-cm Minimum 20 kg-cm Minimum or Near Spin Min.

Wet Stripping TB 114 Pass (90% Minimum) Wet-Track Abrasion Loss One-hour Soak Six-day Soak

TB 100

75 g/ft2 (807 g/m2) Maximum

Lateral Displacement Specific Gravity after 1,000 Cycles of 125 lb (56.71 kg)

TB 147

5% Maximum

2.10 Maximum

Excess Asphalt by LWT Sand Adhesion

TB 109

Classification Compatibility TB 144 11 Grade Points Minimum (AAA, BAA)

The Wet Track Abrasion Test is performed under laboratory conditions as a component of the mix design process. The purpose of this test is to determine the minimum asphalt content required in a slurry seal/micro surfacing system. The Wet Track Abrasion Test is not recommended as a field quality control or acceptance test. ISSA TB 136 describes potential causes for inconsistent results of the Wet Track Abrasion Test.

The mixing test is used to predict the time the material can be mixed before it begins to break. It can be a good reference check to verify consistent sources of material. The laboratory should verify that mix and set times are appropriate for the climatic conditions expected during the project.

The laboratory shall also report the quantitative effects of moisture content on the unit weight of the aggregate (bulking effect) according to AASHTO T19 (ASTM C29). The report must clearly show the proportions of aggregate, mineral filler (if used) and emulsified asphalt based on the dry weight of the aggregate.

The percentage of each individual material required shall be shown in the laboratory report.

Based on the field conditions, adjustments within the specific ranges of the mix design may be required.

The component materials shall be designed within the following limits:

COMPONENT MATERIALS SUGGESTED LIMITS

Residual Asphalt (Slurry Seal)

Type I: 10-16% Type II: 7.5-13.5% Type III: 6.5-12% (Based on dry weight of aggregate)

Residual Asphalt (Micro Surface) 5.5-10% by dry weight of aggregate Mineral Filler 0.0-3.0% by dry weight of aggregate Polymer Content (Micro Surface) Minimum of 3.0% solids based on bitumen wright content Additives As needed Water As required to produce proper mix consistency

12.3 MIX TOLERANCES (SLURRY SEAL)

Tolerances for the slurry seal mixture are as follows:

1. After the residual asphalt content is determined, a variation of ±1% by weight of dry aggregate will be permitted.

2. The slurry consistency, as determined according to ISSA TB No. 106, shall not vary more than ±0.2% (±0.5% cm) from the job mix formula after field adjustments.

3. The rate of application shall not vary more than ±2 lb/yd2 (1.1 kg/m2) when the surface texture does not vary significantly.

General Notes

13. Contractor shall make an examination of the project site and completely familiarize themselves with the nature and extent of the work to be accomplished. No extra compensation will be allowed for any work made necessary by unusual conditions or obstacles encountered during the progress of the work, which conditions or obstacles are readily apparent upon a visit to the site. If there are any questions in this regard or if there are any discrepancies between the plans and the actual site conditions, the contractor shall notify the engineer prior to the submission of bids.

14. All construction operations shall be accomplished in accordance with applicable regulations of the U.S. Occupational Safety and Health Administration. Copies of the OSHA Standards may be purchased from the U.S. Government Printing Office; information and related reference materials may be obtained from OSHA; 903 San Jacinto, Austin, Texas.

Contractor shall comply with all applicable local, state, and federal requirements regarding excesses and waste material, including methods of handling and disposal.

15. Any existing pavement, curbs, and/or sidewalk damaged or removed by the contractor that are not part of this contract are to be repaired by the contractor to at least the preexisting condition at his expense before acceptance of the work.

16. Contractor shall make all due precautions to protect existing facilities from damage. Any damage to existing facilities incurred as a result of these construction operations are to be repaired immediately by the contractor to at least the pre-existing condition at no additional cost to the owner.

17. It shall be the responsibility of the contractor to protect cast iron features from damage which may occur during construction. The Contractor shall replace or repair, as directed by the City, any structures damaged during the life of the contract. No payment will be made for repair or replacement of damaged Items.

18. Contractor is responsible for complying with all applicable environmental laws.

19. The project area and surrounding areas that are utilized by the contractor shall be kept in a neat and orderly manner. Project clean up shall be done daily. Areas that have been chosen by the contractor for storing material and equipment shall be out of public access and not create hazardous conditions for the public. These areas shall be kept in a neat and orderly manner and cleaned daily. Any revegetation of these areas shall be at the contractor’s expense.

20. Any water hauled to the site during the installation shall be paid for by the contractor.

21. The contractor shall not use any facilities of a private property owner without a written agreement that is furnished to the City of Midland. These facilities shall include but not limited to private properties for storage, water, trash receptacles, etc. All City ordinances must be followed.

22. The contractor shall not place spoils on private property without a written agreement that is furnished to the City of Midland.

23. The Contractor is reminded that this project is located in an urban environment, trees and overhead utility lines are common. The Contractor shall provide the proper equipment to complete the work in the urban environment.

EQUIPMENT

24. GENERAL

All methods and equipment employed in performing the work shall be subject to the approval of the Program Manager before work is started and whenever found unsatisfactory, they shall be changed and improved as required. Equipment shall be kept in good working conditions with no leaks. Any equipment that shows signs of leaks shall be fixed immediately and shall not be used until such leaks are fixed. All equipment shall be maintained in satisfactory condition.

The Contractor shall have a minimum of 2 Slurry Seal machines at the project site in good working condition each having a capacity of at least 8 cubic yards to assure sufficient production capability

25. MIXING EQUIPMENT

Micro-Surfacing & Slurry – The material shall be mixed by a self-propelled micro-surfacing mixing machine which shall be a continuous flow mixing unit able to accurately deliver and proportion the aggregate, emulsified asphalt, mineral filler and water to a revolving multi-blade mixer and discharge the mixed product on a continuous flow basis.

The machine shall have sufficient storage capacity for aggregate, emulsified asphalt, mineral filler and water to maintain adequate supply to the proportioning controls. The machine shall be equipped with self-loading devices which provide for the loading of all materials while continuing to lay micro-surfacing, thereby minimizing construction joints.

Individual volume or weight controls for proportioning each material to be added to the mix shall be provided. Each material control device shall be calibrated and properly marked. Scales used for weighing materials and emulsion must be calibrated and meet the requirements of TxDOT Item# 520.

The aggregate feed to the mixer shall be equipped with a revolution counter or similar device so the amount of aggregate used may be determined at any time.

The emulsion pump shall be a positive displacement type and shall be equipped with a revolution counter or similar device so that the amount of emulsion used may be determined at any time.

The mixing machine shall be equipped with a water pressure system and nozzle type spray bar to provide a water spray immediately ahead of and outside the spreader box with 0.05 to 0.15 gallons per square yard.

The mixing machine shall be equipped with an approved fines feeder that shall provide a uniform, accurately metered, predetermined amount of specified mineral filler.

26. Electronic Monitoring System

The micro-surfacing machine shall be equipped with an electronic monitoring system that consists of pulse sensors measuring material delivery rates, a radar gun to monitor distance traveled, and programmable micro-controller, and operators display/input board and an on-board printer.

System shall be capable of monitoring and displaying application rates and use of aggregate, emulsion, fines, water, and additives.

System shall be capable of calculating and displaying ratios of emulsion to aggregate, fines to aggregate, additive to aggregate, water to aggregate, and application rate in pounds per square yard.

System shall be capable of printing a hard copy report on demand which displays the date, weight of aggregate, emulsion, fines, number of gallons of additive and gallons of water, and all the above-mentioned ratios since last reset.

A computer-generated report providing statistics of the workday shall be provided with each hand calculated daily run sheet.

This system shall be accurate to with ½ of a percent of actual weights and measures for all parameters noted above. The system is not expected to calculate quantities and ratios for materials used in handwork and cul-de-sac areas.

The electronic monitoring system shall be accurate to within 0.5% of accurate weights and measures.

Calibrate and properly mark each control device that proportions the individual materials.

Slurry Seal – The slurry seal mixing equipment shall be a continuous flow mixing unit or continuous-run design machines as to give a uniform and complete circulation of the batch in the mixer, so as to not segregate the aggregate, but will provide a thorough and uniform free flowing mix with the asphalt and water. The units shall be equipped with approved devices so that the machine can be accurately calibrated and the quantities of material used can be determined. The mixing machine shall be equipped with a water pressure system and nozzle type spray bar adequate for completely fogging the surface with 0.05 to 0.15 gallons per square yard immediately ahead of the spreader box.

27. SPREADING EQUIPMENT

Spreader boxes shall be kept clean to minimize lumps. Set and maintain the skis on spreader boxes to prevent chatter in the finished mat. Adjust the rear seal to provide the desired spread.

Adjust the secondary strike-off to provide the desired surface texture.

Micro-Surfacing – The surface mixture shall be spread uniformed by means of a mechanical type of spreader box attached to the mixer, equipped with paddles to agitate an spread the materials throughout the box. A front seal shall be provided to ensure no loss of the mixture at the road contact point. The rear seal shall act as final strike off and shall be adjustable. The mixture shall be spread to fill cracks and minor surface irregularities and leave a uniform skid resistant application of material on the pavement, the longitudinal joint where two passes join shall be neat appearing, uniform and lapped.

All excess material shall be removed from the job site prior to opening the road. The spreader box shall have suitable means provided to side shift the box to compensate for variations in pavement geometry.

Slurry Seal – The spreader box shall be equipped to prevent loss of slurry seal from all sides and a flexible rear strike-off capable of being adjusted. It shall provide suitable means for side tracking to compensate for deviations in pavement geometry. The box shall be kept free of build-up asphalt and aggregate. The strike-off drag shall be kept completely flexible at all times.

28. AUXILIARY EQUIPMENT

Suitable crack and pavement cleaning equipment, hand tools and any support equipment will be provided by the Contractor as necessary to perform the work. The Contractor shall use a vacuum equipped street sweeper to remove all swept debris. Sweeping of debris into the gutter shall not be permitted.

29. EQUIPMENT CALIBRATION

Each slurry unit to be used shall be calibrated in the presence of the Program Manager prior to construction. Previous calibration documentation covering the exact materials to be used may be accepted provided they were made during the calendar year. No machine shall be allowed to work on the project until the calibrations have been completed and/or accepted.

LIMITATIONS

30. WEATHER

Air temperature requirements for placing micro-surfacing and/or slurry seal shall be as follows:

November 1 to March 31

a. Micro-surfacing/slurry seal shall not be placed when the air temperate is below 60 degrees F and falling.

b. Micro-surfacing/slurry seal may be placed when the air temperature is above 50 degrees F and rising.

April 1 to October 31

a. Micro-surfacing/slurry seal shall not be placed when the air temperature is below 50 degrees F and falling.

b. Micro-surfacing/slurry seal may be placed when the air temperature is above 50 degrees F and rising.

Surface of roadway must be 60 degrees F or higher prior to placing micro-surfacing/slurry seal to pavement, as determined in the field.

No Micro-Surface/Slurry Seal shall be applied:

In the period following precipitation with water remaining on the surface to be coated.

In foggy conditions.

If there is a threat of rain before the slurry seal can fully cure.

If there is a danger that he finished product will freeze within 24 hours after the application.

If weather conditions prolongs opening to traffic beyond the time specified by the Program Manager.

The Micro-Surfacing/Slurry Seal will be placed on the location and within the time limits as specified by the Program Manager.

31. CONDIDITON AND TYPE PAVEMENT TO BE TREATED

Any base failures, severe pavement defects, or similar conditions which are present will be properly repaired by the City to ensure correct application and performance of the slurry. Slurry normally adheres to asphalt pavement more readily than concrete, especially worn or polished areas. Heavy traffic areas, especially those on concrete, require greater care in selection type of coarseness of slurry allowing the surface to fully cure before opening to traffic, and the placing of either a tack coat or a second coat of slurry for greater adhesion and wear purposes.

32. NOTIFICATIONS

Contractor shall provide and distribute notice to all impacted residents and property owners at least three (3) days prior to beginning work.

Contractor shall indicate application time and when the surface can be used. If necessary, include a map showing closed-off areas.

Provide the name of the company and the phone number of a person of authority on site who represents the CONTRACTOR who can be reached at any time during the work.

Warn of potential vehicle tow away and other construction issues affecting the neighborhood.

Should work not occur on a specified day after the notices have been distributed, the contractor shall issue an updated notice.

A copy of the notice shall be submitted to the Transportation Division prior to the beginning of the project for approval.

If the City of Midland supplies the Contractor with notices, the Contractor shall distribute the City supplied notices instead of their own three (3) days prior to beginning work.

33. TRAFFIC CONTROL

Care shall be used to create a safe work area, with minimal impact on the flow of traffic. Control of vehicular and pedestrian traffic is of the utmost importance to the City of Midland. A traffic control plan designed to meet the sequence of construction established by the contractor shall be submitted to the City of Midland’s Traffic Operations Division no less than 48 hours prior to the beginning of construction. Construction cannot begin without a traffic control plan approved by the City of Midland’s Traffic Operations Division. The plan shall be detailed for the Sequence of work and not generic. The plan shall be followed at all times. The contractor shall place personnel in charge of the traffic control operation who have been trained in flagging procedures and in barricade and signage operations. In the event the traffic control plan or the traffic operation is not being conducted in the correct manner or according to the approved plan, construction activities shall be stopped until the traffic control procedures are corrected.

It shall be the Contractor’s responsibility to provide adequate traffic control measures, such as barricades, cones advance warning signs, flag person, etc. to protect the uncured micro/slurry from all types of traffic and provide traffic safety in the construction area. All barricades, signs and traffic control for this project shall conform to the latest edition of the Texas Manual on Uniform Traffic Control Devices (TMUTCD). Opening to traffic does not constitute acceptance of the work.

Any damage to the uncured slurry will be the responsibility of the Contractor and will be repaired as directed by the Program Manager. Approved temporary lane marking will be provided by the Contractor for placement if the street was previously striped.

The Contractor shall be responsible for the traffic control plan and shall submit the plan to the Traffic Operations Division for approval before commencing work. The Contractor shall plan and layout the work such that no traffic is allowed on new pavement while the asphalt work is being placed. All traffic control shall be in accordance with TMUTCD standards.

Residential streets and minor collectors may be closed during construction; however, access to properties adjacent to the work zone shall be maintained at all times unless otherwise approved by the City. Contractor shall limit the number of consecutive residential and minor collector street closures. A minimum of two travel lanes (one for each direction) shall remain open at all times on all arterial streets.

34. TEMPORARY MARKINGS AND LANE DELINEATION

Whenever the work causes obliteration of pavement markings or delineation, temporary markings or delineation shall be in place prior to opening the traveled way to public traffic. Lane line and centerline pavement delineation shall be provided at all times for traveled ways open to public traffic. Other markings such as crosswalks, stop bars, and pavement arrows shall be delineated prior to opening the roadway to public traffic.

All work necessary to establish satisfactory temporary markings and line delineation shall be performed by the Contractor. Surfaces on which temporary marking and line delineation is to be applied shall be cleaned of all dirt and loose material and shall be dry when it is applied.

Temporary markings and line delineation shall be maintained until replaced with permanent markings.

Temporary lane delineation shall consist of either a 4-inch by 4-inch square stripe or a 4-inch reflectorized tab, as directed by the Program manager. Temporary lane delineators shall be placed on lane lines and centerlines at longitudinal intervals of not more than 40 feet apart, or 12 feet apart on radii. The temporary markings and lane delineators shall be the same color as the lane line, centerline, or pavement marking being replaced.

If used, tabs shall be in accordance with Item 662 of the Texas Department of Transportation’s Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges, latest edition. The contractor shall replace temporary road marker tabs as necessary throughout the project until permanent pavement markings are installed and shall remove all tabs with installation of permanent markings. The placement, maintenance, and eventual removal of temporary lane markers shall be performed by the Contractor and be incidental to the project.

STORAGE AND STOCKPILING

35. STOCKPILING OF AGGREGATE

Precautions shall be taken to ensure the aggregate does not become contaminated with oversized rock, clay, silt, or excessive amount of moisture. The Contractor shall be required to utilize a screening plant to remove oversized particles from the aggregate at the stockpile site.

The stockpile shall be kept in areas that have good drainage. Segregation of aggregates proposed for use and as supplied to the mixing plant shall be uniform.

36. STORAGE SITE

The Contractor shall provide a suitable storage facility for all equipment and materials needed to perform the work. This site should be located as close as possible to the area of work being done to reduce turnaround time and ensure an acceptable rate of work. Any site selected shall be subjected to final approval by the Program Manager. Erosion control measures shall be implemented as needed to comply with the law and City of Midland ordinances.

37. SURFACE PREPARATION

The existing roadway surface shall be thoroughly clean and free of all vegetation, loose aggregate, other loose materials, and soil and approved by the City inspector before placement.

Equipment, labor and materials required by this item shall be incidental to the project.

Any breakdowns, base failures, or other defects will be properly repaired by the City before application of the slurry seal begins. Manholes, valve boxes, grate inlets, concrete collars, and other designated objects shall be covered by the Contractor to ensure their integrity. After completion of slurry placement, the Contractor shall remove said covers so the objects protected will remain fully functional. Any objects damaged by the Contractor shall be repaired or replaced at no cost to the City.

Existing raised pavement markers and thermoplastic markings wider than 6” shall be thoroughly removed. Grind off all existing raised stop bars, turn arrows, railroad crossings, cross walk markings, and any other pavement markings that are wider than 6”. All 6” lane striping may be left to be covered with the new micro-surfacing layer (unless otherwise directed by the Program Manager or the Traffic Engineer).

APPLCATION

38. GENERAL

If conditions require, the pavement shall be pre-wetted by fogging ahead of the spreader box.

Water used in fogging the surface shall be applied so that the entire surface is damp with no flowing water in front of the box.

39. RATE OF APPLICATION

The slurry shall be sufficiently stable during the spreading period so that the emulsion does not break, there is no segregation of the fines from the coarser aggregate and the liquid of the mix does not float to the surface.

The Slurry Seal mix shall be Type II Gradation and spread uniformly at a rate of not less than 15 pounds of dry aggregate per square yard and no more than 20 pounds of dry aggregate per square yard, or as directed.

Micro-surfacing shall be either the TxDOT Grade II or the Type II Gradation and the mix shall be spread uniformly at a rate of not less than 25 pounds of dry aggregate per square yard and no more than 30 pounds of dry aggregate per square yard, or as directed.

40. Rutting on Major Thoroughfares and Collector Streets—Micro-Surface

Shallow ruts that are less than ½ inch in depth may be covered by a full width scratch box utilizing a steel primary strike-off plate.

Ruts that are between ½ inch and 1 inch in depth shall be filled independently with fixed width spreader box no more than 6 feet wide. The rut filling box shall have a steel primary strike-off plate that is the same width as the spreader box.

Ruts that are in excess of 1 inch in depth shall be filled with a 5-foot wide rut filling spreader box specifically designed to fill wheel path ruts. This operation will require multiple placement passes to restore the pavement to its original cross section. Special care shall be used by the Contractor to ensure that the material has proper time to dry between applications to promote bonding between the original pavement and the micro-surfacing pavement.

Maximum micro-surfacing thickness applied as rut filling shall not exceed 1 inch for each pass required to restore pavement to the original profile.

41. Scratch Course—Micro-Surfacing

All “Scratch Course” applications shall be performed utilizing a steel primary strike-off plate. This will allow the bottom, or “scratch course,” to mitigate any irregularities and have a more uniform profile for the micro-surfacing pavement to be applied to.

42. Asphalt Milling at Concrete Intersections Thoroughfares and collector streets which have concrete intersections or where concrete valley gutters intersect the street and that have pre-existing rough or bumpy transitions shall have the asphalt surface grinded to such a depth as to allow a smooth transition between concrete and the completed micro-surfacing pavement. Smooth concrete/asphalt joints do not require grinding prior to the micro-surface placement.

43. JOINTS

No excessive buildup or unsightly appearance shall be permitted on longitudinal or transverse joints. An excessive overlap will not be permitted on longitudinal joints. The Contractor shall provide suitable width spreading equipment to produce a minimum number of longitudinal joints throughout the project. Longitudinal joints shall be placed on lane lines when possible. If half passes are used they shall not be the last pass of any paved area. Joints and edges shall be uniform and neat in appearance.

44. HAND WORK

In areas where the spreader box cannot be used, the slurry/micro shall be applied by hand squeegees to provide complete and uniform coverage. Any joint or cracks not filled by the slurry/micro shall be corrected by use of hand squeegees. Hand work shall be completed during the machine applying process. Due to difficulty in hand working micro-surfacing material due to the quickset nature of the emulsion, handwork areas should be kept to a minimum.

Contractor is not required to treat the area at the end of radii (ER) of streets at intersections unless:

The intersecting street is also scheduled to receive the surface treatment.

The ER is located at the end of work at an intersection where the continuing street is not receiving the surface treatment.

The project manager makes a special request.

45. LINES

Straight lines along curb gutters and shoulder will be required. No runoff on these areas will be permitted. Lines at intersections shall be kept straight to provide a good appearance. Slurry shall be placed at the lip of the gutter or at a distance from the face of the curb as directed by the Program Manager.

Mask of the ends of intersections and other ends of work where the abutting surface does not receive the surface treatment in order to produce a crisp and straight line.

46. MANHOLES AND VALVES

Special care shall be taken by the contractor to ensure that all manholes, water valves, concrete collars, and other surface structures are sufficiently protected from the micro-surfacing/slurry process by the use of a plastic membrane covering or other approved method.

Contractor shall be responsible for removing the coverings after the surface treatment has cured.

The cost of this work shall be incidental to the project.

47. CURING

Micro-Surface –all traffic shall be kept off the micro until it has cured to a firm condition that will prevent damage to the micro. The emulsified asphalt shall be so formulated that when the paving mixture is applied with the relative humidity at no more than 50% and ambient air temperature of at least 75 degrees Fahrenheit, it will cure sufficiently such that uniformly moving traffic can be allowed on completed travel lanes within 1 hour after placement with no damage to the surface. Failure to comply with this requirement may result in cessation of all the work until such time that the Contractor provides the proper adjustments in his operations. If determined necessary by the Program Manager, the mixture properties shall be adjusted according to humidity conditions and ambient air temperatures to allow uniformly moving traffic on completed travel lanes within 1 hour after placement with no damage to the surface. Failure to comply with this requirement may result in cessation of all the work until such time that the Contractor provides the proper adjustments in his operations. Protect other locations subject to sharp turning or stopping and starting traffic for longer periods when necessary. Any uncured micro damaged will be repaired to the satisfaction of the Program Manager at the Contractor’s expense.

Slurry Seal - all traffic shall be kept off the slurry until it has cured to a form condition that will prevent damage to the slurry. Any uncured slurry damaged will be repaired to the satisfaction of the Program Manager at the Contractor’s expense.

48. FINISHED SURFACE

Micro-surfacing and slurry finished grade shall be uniform in texture and free from excessive scratch marks, tears, holes, bare spots, cracks, and other surface irregularities. All such irregularities shall be repaired by the Contractor at their own expense.

Longitudinal joints shall be placed on lane lines unless otherwise directed by the Program Manager.

Joints and edges shall be uniform and neat in appearance. Mask off end of streets and intersections to provide straight lines.

Make straight lines along the lip of gutters and shoulders. Keep the same thickness in these areas. No runoff on these areas will be permitted.

Avoid unsightly appearance from hand work.

Micro-Surface—all ruts, utility cuts, and depressions in the surface shall be filled in a separate pass from the final pass.

Protect surface treatment materials from traffic until it has cured.

49. CLEAN-UP

All objects covered (manhole covers, valve covers, grate inlets, concrete collars, etc.)

shall be restored to their original integrity. The Contractor shall remove all unused material and debris from the sire prior to final acceptance.

The Contractor shall thoroughly clean any curbs, sidewalks, guardrails, guide posts, etc.

that receives any splatter, mar or overcoat from the surface treatment application.

50. SUBCONTRACTING

The Contractor agrees that it will retain personal control and will give its personal attention to the fulfillment of this contract. The Contractor further agrees that subletting of any portion or feature of the work, or materials required in the performance of this contract, shall not relive the Contractor from its full obligations to the Owner, as provided by the contract documents.

51. WARRANTY

The Contractor shall provide a one (1) year minimum warranty when the existing pavement is in an appropriate condition (Contractor to determine condition). Warranty covers delaminating, peeling, and premature surface wear (raveling, shedding, or the loss of aggregate that is not typical).

a. Before placement notify the Engineer if pavement condition or application condition voids the warranty.

b. Engineer may allow or cancel product application at no cost to OWNER if warranty cannot be given.

Acceptable performance after one (1) year period is no delaminating, peeling, or inter-aggregate loss in surface wear. Mechanical disturbances by snow plow chatter, studded tires, etc, are excluded from warranty. Repair defective coverage at no additional cost to OWNER.

52. PROJECT SCHEDULE

It shall be the responsibility of the contractor to provide a project schedule to City staff prior to construction. The schedule should outline the anticipated start and end dates for each phase of the surface seal project.

The project shall be completed no later than August 31, 2026.

53. ADDITIONAL NOTES

All temporary erosion and sedimentation (e&s) control measures must be properly selected, installed, and maintained in accordance with the manufacturer’s specifications and good engineering practices. Erosion controls protection shall also be placed at storm drain inlets in the work zone. If inspection indicates a control has been used inappropriately, or incorrectly, the Contractor must replace or modify the control for site situations. The controls must remain in place until disturbed areas are revegetated and the areas have become permanently stabilized.

Litter, construction debris, and construction chemicals exposed to storm water shall be prevented from becoming a pollutant source for storm water discharges (E.G., screening outfalls, picked up daily).

PAY ITEM NOTES

1. Mobilization, Job Site Safety, Erosion Protection, and Traffic Control.

Unit payment shall be lump sum, full compensation for all mobilization/demobilization and project-wide temporary controls required to safely complete the work. This includes mobilization/demobilization of crews, equipment, and support vehicles; move-ins between segments as required. Project supervision and coordination related to safety/traffic control. Job site safety measures (signing, devices, flagging, temporary delineation, daily set-up/removal, maintenance). Temporary erosion/sediment control and protection of adjacent drainage features as required for operations. All materials, equipment, labor, tools, power, and transportation necessary to implement and maintain these requirements.

2. Micro-surfacing in accordance with City of Midland’s Micro-Surfacing Specifications. The unit of payment shall be square yards of micro-surfacing place and accepted in accordance with the City’s Micro-Surfacing Specifications. This work includes: furnishing micro-surfacing materials;

proportioning/mixing; hauling; placement; spreading; handwork; and curing per specification.

Protection of fresh micro-surface until opened to traffic. All materials, equipment, labor, tools, power, and transportation necessary to complete the item.

3. Asphalt Milling at Concrete Intersections/Concrete VG Tie-ins. Unit of payment shall be square yards of asphalt milled to the specified depth and accepted. This work includes equipment, labor, layout, milling/grinding operations, cleanup/sweeping, handling/hauling and proper disposal of milling, and all incidentals necessary to complete the work.

4. Thermoplastic Grinding. Unit of payment shall be square feet of thermoplastic pavement marking grinding completed and accepted, within the limits directed for the project. This work includes grinding/removal of existing thermoplastic markings as required to prevent “ghost outlines” and conflicts. Collection and disposal of grindings/debris; sweeping/cleanup. Protection of the roadway surface and adjacent improvement during removal operations. All materials, equipment, labor, tools, power, and transportation necessary to complete the work.

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